Experimental Implant Could Dispense Drugs Inside Joints During Arthritis Flares

By Crystal Lindell

Researchers in the UK are developing an artificial cartilage that could dispense anti-inflammatory and pain relieving medications from within joints during an arthritis flare-up.

The gel-like material, developed by a team at the University of Cambridge, has been designed to respond to changes in pH, a measure of acidity. During flare-ups, arthritic joints become inflamed and slightly more acidic than the surrounding tissue.

As acidity increases, the polymer implant becomes softer and more jelly-like, triggering the release of drug molecules within the joint. In theory, researchers say the drugs would be released precisely where and when they are needed, providing more effective and continuous relief.

“These materials can ‘sense’ when something is wrong in the body and respond by delivering treatment right where it’s needed,” said Stephen O’Neill, PhD, a postdoctoral researcher at Cambridge. “This could reduce the need for repeated doses of drugs, while improving patient quality of life.”

The research was reported in the Journal of the American Chemical Society. 

The polymer material was developed by a research group in the Department of Chemistry at Cambridge that specializes in designing and building unique materials for a range of potential applications.

“For a while now, we’ve been interested in using these materials in joints, since their properties can mimic those of cartilage,” said lead author Oren Scherman, PhD, Director of the Melville Laboratory for Polymer Synthesis. “But to combine that with highly targeted drug delivery is a really exciting prospect.”

Clinical trials are needed before the material can be used in patients. Researchers say their next steps will be to test the materials in living organisms to evaluate their performance and safety. 

If successful, that could lead to a new generation of responsive biomaterials capable of treating a variety of chronic diseases. The gel could be adapted for placement in different parts of the body.

“It’s a highly flexible approach, so we could in theory incorporate both fast-acting and slow-acting drugs, and have a single treatment that lasts for days, weeks or even months,” said O’Neill.

While it is incredible to see these new advances in pain treatment, it’s also imperative that researchers make sure that they are actually better than the current treatments available. They also need to make sure that the implants are relatively easy to remove in the case of complications.

In the research paper, the authors suggest the implants could be used for rheumatoid and osteoarthritis pain. However, both of those diseases can cause widespread joint pain, so it remains unclear if material needs to be implanted in multiple joints to be effective.

And if the implants can be effective “for days, weeks or even months,” how would they be re-loaded with medication or even fully replaced? Such a process could be very taxing for patients, especially if it requires a trip to the hospital or a doctor’s office each time.

In the original Jurassic Park movie, the character Dr. Ian Malcolm says, “Your scientists were so preoccupied with whether they could, they didn't stop to think if they should.”

I hope these researchers heed that advice.